In a world of emerging technologies and medications, sensing and detection is of paramount importance for the accurate diagnosis of illness and disease. This project explores the development of a point-of-care biosensor for the detection of both cortisol and human growth hormone, basing their capture and detection on two main antibodies.
There is currently no single sensor that could simultaneously detect both cortisol and growth hormone, two essential hormones that are produced by the hypothalamic-pituitary-adrenal axis. However, there is a market for such a device, which would prove useful in, not only the non-invasive diagnosis of diseases such as Addison’s disease, Cushing’s syndrome and dwarfism, but also in identifying tumours in the hypothalamus, pituitary and adrenal glands. The hypothalamus-pituitary-adrenal axis is complex and dependent on many factors however, generally, increased cortisol production is the hypothalamus-pituitary-adrenal axis’s physiological response to an external stressor. Growth hormone is also regulated through the hypothalamus-pituitary-adrenal axis and secreted from the anterior pituitary gland. Hence a multiplex point-of-care sensing device for the quantification of both cortisol growth hormone would be multifaceted for the unintrusive diagnosis of hypothalamus-pituitary-adrenal axis activity and the practical uses of stress indicator would be diverse and include the medical and pharmaceutical sector as well as sport and performance.
A range of sensing is explored including enzyme-linked immunosorbent assay, cyclic voltammetry and impedance methods. It is intended that the final biosensor is based on electrochemical impedance spectroscopy due to the high sensitivity, accuracy and versatility associated with impedance. The final ensemble was based on inexpensive screen-printed electrodes and was able to detect cortisol between 30-300 ng/mL and recombinant growth hormone for the range of 5-30 ng/mL.